This week we get a reveal that there will be a new weekly article coming out next week, where James Wyatt will talk about the "story behind the world". Hopefully this means that we will get some semblance of a default campaign setting, though I am stoked about getting a peak into general flavor content. Jon also wraps things up by asking a familiar question; what does a paladin look like?
As with the wizard that depends on a bunch of factors: race, country of origin, upbringing, climate, culture, how she became a paladin (did she choose, or was she chosen?), what god does she serve (if required), etc. Given all of these factors, I can make a case for a paladin to dress, wield, and act almost any way she wants (and "appear" like most any class).
The whole “knight in shining armor” look, while iconic, should not be necessary. In “vanilla” campaigns I could see paladins of Pelor, Moradin, and Erathis going that route, but not necessarily Sehanine or Kord. A paladin might wear simple clothing, donating all but the necessities to those less fortunate. She might wear an elaborate tabard befitting her station. A champion of a nature deity might clad herself in rough-hewn skins, while one of a god of death would shroud herself in dark colors.
When compared specifically to the fighter it could be really hard to differentiate the two. I mean, both can wear holy symbols, the same armor, and wield the same weapons. A code of honor is not just a class feature, and neither is a particularly chivalrous personality; the fighter and paladin could be mistaken by those who tend to judge stereotypes, especially if the fighter likes to keep her gear clean and the paladin follows the tenants of Moradin, drinking it up in a tavern and causing brawls after hours.
The main difference that I can infer from what we have been told is that the fighter will be more skilled with weapons, while the paladin will be able to levy divine retribution.
I would like to see an edition where paladins are not all wearing full plate, packing longswords, and/or riding atop horses. You can give us that, but also something different, like that Wayne Reynolds drawing from Defenders of the Faith of the guy on the armored lion; show us paladins from a variety of races, cultures, and gods. Like, halflings with shortbows on riding dogs, elves with spears on stags or wolves, etc. Most importantly, cleave to 4th Edition and give us options that still work.